Oorschot. A white-box DES implementation for DRM applications

Abstract. For applications such as digital rights management (drm) solutions employing cryptographic implementations in software, whitebox cryptography (or more formally: a cryptographic implementation designed to withstand the white-box attack context) is more appropriate than traditional black-box cryptography. In the white-box context, the attacker has total visibility into software implementation and execution, and our objective is to prevent the extraction of secret keys from the program. We present methods to make key extraction difficult in the white-box context, with focus on symmetric block ciphers implemented by substitution boxes and linear transformations. A des implementation (useful also for triple-des) is presented as a concrete example.